The simba viscosity yacho Urume. Chii zvayo mumuviri zvokuimba nechinangwa?

The mvura kunorondedzerwa se muviri, anogona kuchinja chimiro chayo pagungano pamadiro duku simba pamusoro payo. Kazhinji pane mhando mbiri chikuru mvura uye magasi donhwe. Donhwe Urume - imwe mvura iri senguva mupfungwa: mvura, mafuta neparafini, mafuta nezvimwewo. Gaseous zvinwiwa - magasi izvo pasi kwomuzvarirwo ezvinhu Somuenzaniso, gaseous zvinhu zvakadai semhepo, senitrogen, propane, okisijeni.

yeimwe izvi zvisingapindirani samolecular marongerwo uye mhando nesungano pakati mamorekuru pamwe mumwe. Zvisinei, kubva nemaonero makanika, ivo chichiitwa vezvenhau. Uye nemhaka iyi, nokuti akataura zvimwe zvemaziso maitiro: arambe achirema uye yakananga nerukudzo; uye zvinhu zvinooneka zvivako: compressibility, chafariz kuwedzera, simba tensile, simba pamusoro pemvura kusawirirana uye viscosity.

Under viscosity kunzwisisa pfuma ine mvura nenhumbi kudzivisa zvishoma nezvishoma mumatope kana kuizunguza ayo akaturikidzana kune mumwe. Musimboti zvinenge panowanikwa kukweshera mauto pakati akasiyana akaturikidzana mukati Urume panguva yavo hama inofamba. Kusiyanisa pakati pfungwa "viscosity guru pamusoro Urume" uye ayo "kinetic viscosity". Next, kunyatsotarisisa, chii musiyano pakati izvi pfungwa.

Basic Pfungwa uye divi

Viscous simba F, izvo unovapo kutamira hama mumwe pedyo akaturikidzana of generalized Urume kubva pane Proportional zvakananga velocity pakati akaturikidzana vavo kuonana nharaunda S. uyu simba mabasa mugwara perpendicular kuti inofamba, uye runoratidzwa Newton mukana wokuti vanhu vanga iri analytically

F = μS (ΔV) / (Δn),

apo (ΔV) / (Δn) = GV - the velocity gradient nenzira zvakajairika zvinofamba zvikamu.

The proportionality coefficient μ - ndiro simba viscosity, kana kungoti viscosity generalized Urume. Kubva Newton kuti equations zviri

μ = F / (S ∙ GV).

In mumuviri kuyerwa hurongwa chairema viscosity rinorondedzerwa so viscosity ari svikiro, iyo panguva chikwata velocity gradient GV = 1 masendimita / chik chete mativi sendimita kuti rukoko frictional simba mabasa muna 1 dyne. Nokudaro, divi rimwe chikwata munyika ino kunoratidzwa dynes ∙ S ∙ masendimita ^ (- 2) = R ∙ masendimita ^ (- 1) ∙ S ^ (- 1).

chiyero Izvi zvinonzi simba viscosity nechivimbo (P).

1 P = 0.1 Pas ∙ C = 0,0102 kgf ∙ pamwe ∙ M ^ (- 2).

Shandisa uye zviyero duku, okuti: P 1 = 100 centipoises (cps) = 1000 mPas (millipuaz) = 1000000 INC (mikropuaz). Munyika hwokugadzira marongedzero nokuda Unit viscosity mutengo achitora kgf ∙ pamwe ∙ M ^ (- 2).

Munyika dzakawanda hurongwa chairema viscosity rinorondedzerwa so viscosity ari svikiro, iyo panguva chikwata velocity gradient GV = 1 m / S 1 M chete mativi mita nemvura rukoko nokuita kukweshera simba 1 N (Newton). The divi tsika μ mu ari SI runoratidzwa makirogiramu ∙ M ^ (- 1) ^ ∙ ne (- 1).

Uyezve Unhu dzakadai simba viscosity mvura akasuma pfungwa sezvo nhamba yacho kinematic viscosity coefficient μ kuti mvura mvura arambe achirema. The kukosha kinematic viscosity akayera muna Stokes (1st Zvinokonzerwa = 1 masendimita ^ (2) / c).

The viscosity coefficient iri dziwande kuenzana nokuwanda motokari vakatakura iri zvinofamba gasi paminiti chikwata nguva mugwara perpendicular kuti sangano, paminiti chikwata nharaunda kana kufamba nokukurumidza akasiyana paminiti chairema velocity kupinda gasi akaturikidzana akaparadzaniswa muzana chikwata kureba. Viscosity coefficient kunobva mhando uye mamiriro acho (tembiricha uye kumanikidzwa).

Dynamic viscosity uye kinematic viscosity kuti mvura uye magasi, kusvikira pamwero mukuru kuvimba tembiricha. Zvakanga vakaona kuti zvose coefficient kuderera muwanze tembiricha kuti anodonha mura uye, Ukuwo, unowedzerawo tembiricha inokwira - nokuti magasi. Kusiyana kutsamira zvinogona kutsanangurwa kwomuviri hunhu nesungano pakati mamorekuru vari droplet mvura uye magasi.

The panyama zvinoreva

Kubva omunyori samolecular kinetic dzidziso magasi viscosity Fani iri pakuti zvinofamba svikiro nokuda kurongwa inofamba pakati mamorekuru kunoitika kunangiswa akaturikidzana kuti aimhanya siyana. Saka, kana zvakaturikidzaniswa wokutanga mugwara chichifamba nokukurumidza kupfuura pedyo pawo kechipiri layer zvakaturikidzaniswa rechipiri rokutanga kutamira nokukurumidza Morekuru, ndiEzekieri.

Saka, kutanga rukoko ruchigona mhanyisa sangano rechipiri layer uye wechipiri - kuderedza kufamba rokutanga. Saka, yaipedzerwa kufamba wokutanga wokutanga vachava kuderera, uye wechipiri - kuwedzera. The zvichiguma shanduko iyi kwazvo inofamba iri dzinoratidzwa viscosity coefficient kune magasi.

The droplet kusiyana magasi, dzomunyika kukweshera rukuru zvakadini nokuda kuitwa intermolecular mauto. Uye, sezvo kure pakati mamorekuru nemvura droplet iri diki sezvo zvichienzaniswa gaseous runyararo, kuti samolecular kusakarongeka mauto apo - chinokosha. The mamorekuru nemvura, uyewo mamorekuru nezvishoma, kutangira pedyo zvakanyatsoenzana pfungwa. Zvisinei, mune mvura, zvokudya izvi hazvisi mira. Pashure mumwe nemvura Morekuru payakakurudzirwa nguva kuva itsva chinzvimbo. Panguva iyoyowo, panguva iyo nzvimbo mamorekuru iri mvura haachinji, nguva akaitumidza "upenyu aivapo".

Intermolecular mauto kuvimba yekudyidzana pamusoro mhando emura. Kana viscosity pamusoro fuma iri diki, inonzi "flowable", sezvo kuerera coefficient uye simba viscosity of Urume - iri inversely Proportional. Ukuwo, mumwe zvinhu rurefu viscosity angava zvokuimba zvakaoma, sezvo Somuenzaniso, nebwe. The viscosity of fuma apo yekudyidzana kunoenderana Zvinoumba netsvina vavo mari uye tembiricha. With kuwedzera tembiricha nhamba yemabhuku "ndakagara upenyu" nguva ipfupi, nokudaro kuwedzere Urume viscosity kunodzikira uye kufamba ane fuma.

Chiitiko kuti viscosity, uyewo mamwe samolecular chokufambisa mananara (diffusion uye chafariz conductivity) chinhu kusingarapiki muitiro inotungamira kuna kubudirira ane zvakanyatsoenzana ehurumende chaienzanirana kunonyanyisa entropy uye wakasununguka simba zvishoma.